围压作用下再生混凝土细观数值模拟研究

Mesoscopic Numerical Simulation of Recycled Concrete under Confining Pressure

为对高围压下再生混凝土进行细观分析,在有限元软件中应用改进的混凝土塑性损伤模型,通过Python建立五相随机骨料模型,探究3、15及24 MPa围压下不同再生粗骨料取代率时的混凝土应力-应变曲线与损伤破坏形态。结果表明:该材料模型的准确度远高于传统模型,其应力-应变曲线发展趋势及结果与试验值基本相同,最大差距不超过10%;该方法能有效模拟混凝土在围压下的力学性能,低围压时混凝土的破坏裂缝较多,高围压时混凝土产生的初始裂缝较多,但最终只会形成1条破坏裂缝。

To perform a microscale analysis on recycled concrete under high confinement pressure,an improved concrete damage plasticity model was applied to finite element software.A five-phase random aggregate model was established using Python to investigate the stress-strain curve and damage failure morphology of concrete under 3,15,and 24 MPa confinement pressures with different replacement rates of recycled coarse aggregates.The results show that the accuracy of this material model is much higher than that of traditional models,and its stress-strain curve development trend and results are basically the same as the experimental values,with a maximum difference of no more than 10%;This method can effectively simulate the mechanical properties of concrete under confinement pressure,when the confinement pressure is low,there are more failure cracks in the concrete.When the confinement pressure is high,there are more initial cracks in the concrete,but ultimately only one failure crack will form.